The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
Turbochargers are used for many applications. A turbocharger includes a pump portion and a turbine portion. Turbochargers are used for recovering energy from a pressurized stream of fluid. Excessive pressure in the turbine portion is used to drive the pump portion. One use for a turbocharger is recovering energy from a brine outlet of a reverse osmosis membrane assembly.
Reverse osmosis systems operate in a wide range of operating conditions for any given flow while seeking to maintain a high level of performance. Various turbine configurations are known for improving levels of performance for the turbine.
In one known turbine, single volute nozzle volute systems use a valve stem to allow bypass fluid from the turbine inlet to the impeller. Some improvement in performance is achieved. A valve is used to control the amount of fluid in the bypass. Manually controlled valves require a person to physically move the control wheel using high torque. This is not practical especially in systems with multiple stages. Electrically controlled valves can be automated. However, due to the high torque involved in turning the valves, the systems for rotating the valves are expensive.